On Fri, Dec 11, 2020 at 05:44:26PM +0200, Iskren Chernev wrote:

On 12/11/20 9:47 AM, Krzysztof Kozlowski wrote:

quoted

On Thu, Dec 10, 2020 at 10:25:34PM +0100, Krzysztof Kozlowski wrote:

quoted

Interrupt line can be configured on different hardware in different way,
even inverted.  Therefore driver should not enforce specific trigger
type - edge falling - but instead rely on Devicetree to configure it.

The Maxim 14577/77836 datasheets describe the interrupt line as active
low with a requirement of acknowledge from the CPU therefore the edge
falling is not correct.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>

---

This patch should wait till DTS changes are merged, as it relies on
proper Devicetree.
---
.../devicetree/bindings/power/supply/max17040_battery.txt       | 2 +-
drivers/power/supply/max17040_battery.c                         | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git

a/Documentation/devicetree/bindings/power/supply/max17040_battery.txt
b/Documentation/devicetree/bindings/power/supply/max17040_battery.txt

quoted

quoted

index c802f664b508..194eb9fe574d 100644

--- a/Documentation/devicetree/bindings/power/supply/max17040_battery.txt
+++ b/Documentation/devicetree/bindings/power/supply/max17040_battery.txt

@@ -39,7 +39,7 @@ Example:

         reg = <0x36>;
         maxim,alert-low-soc-level = <10>;
         interrupt-parent = <&gpio7>;
-        interrupts = <2 IRQ_TYPE_EDGE_FALLING>;
+        interrupts = <2 IRQ_TYPE_LEVEL_LOW>;
         wakeup-source;
     };

diff --git a/drivers/power/supply/max17040_battery.c

b/drivers/power/supply/max17040_battery.c

quoted

quoted

index d956c67d5155..f737de0470de 100644

--- a/drivers/power/supply/max17040_battery.c
+++ b/drivers/power/supply/max17040_battery.c

@@ -367,7 +367,7 @@ static int max17040_enable_alert_irq(struct

max17040_chip *chip)

quoted

quoted

     flags = IRQF_TRIGGER_FALLING | IRQF_ONESHOT;

This has to be removed. I will fix it in v2.

Best regards,
Krzysztof

I removed the IRQF_TRIGGER_FALLING, tweaked the DT as per the DT patch, and
it worked on the samsung klte.

I don't understand how the DT irq flag ends up being used by the kernel. It
is never explicitly read from DT or passed to interrupt API, only i2c->irq,
which is a pure int.

The core __setup_irq() calls irqd_get_trigger_type() on IRQ data
matching the IRQ.

Best regards,
Krzysztof

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